A continual objective in the food processing industry is to prevent unacceptably high levels of microbial activity on the food products themselves and on devices for processing the food products that contact the food products. Another objective is to reduce costs associated with the processing of food products. Costs can be reduced by increasing productivity, including both increasing the rate at which food is processed and reducing any periodic down time necessary for cleaning.
Steam pasteurization has been used to heat the surface of food products, such as meat, to treat the surface in a non continuous manner where a piece of meat is stopped in a steam region and steam is directed at the meat while stopped. For example, U.S. Pat. No. 6,291,003 discloses an apparatus having three regions separated by doors, a dewatering region, a steam region, and a coolant region. A controller controls a conveyor to move meat between the three regions, including stopping the conveyer in the steam region for the application of steam.
A problem with typical steam treatment methods and devices is that the steam tends to form condensate on the outer surfaces of the food product. The condensate is formed rapidly as the high temperature steam first contacts the much lower temperature food product. Once a condensate layer forms on the outer surface of a food product, the condensate acts as a barrier to additional heat transfer from high temperature steam. Thus, when steam condenses to form condensate on an outer surface of a food product, the effectiveness of the continued steam treatment is significantly lowered.